Replace fragment in ActionBar Tabs that have swipe view

Question

I did a quick search in here and didn't find any answers for my qustion, if its already answered please point me to that question ..

I have an ActionBar Tabs with swipe views implemented according to this android training. My activity have 3 tabs Weather Comment Dashboard and these fragments
WeatherFragment CommentsFragment LoginFragment DasboardFragment RegisterFragment

As the activity is started, Weather Tab displays WeatherFragment , Comments Tab displays CommentsFragment and Dashboard Tab displays LoginFragment

If Login is successful in LoginFragment, DasboardFragment should replace the LoginFragment inside the Dashboard Tab. So if user swipes to other tabs and come back to Dashboard Tab DasboardFragment should be visible.

I'm new to android development, so any code snippets or tutorial would be greatly appreciated

Code i've so far MainActivity class

public class MainActivity extends FragmentActivity implements
    ActionBar.TabListener {

AppSectionsPagerAdapter mAppSectionsPagerAdapter;
ViewPager mViewPager;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_get_network_weather);

    mAppSectionsPagerAdapter = new AppSectionsPagerAdapter(
            getSupportFragmentManager());

    final ActionBar actionBar = getActionBar();
    //actionBar.setDisplayShowTitleEnabled(false);
    //actionBar.setDisplayShowHomeEnabled(false);
    actionBar.setHomeButtonEnabled(false);
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
    mViewPager = (ViewPager) findViewById(R.id.pager);
    mViewPager.setAdapter(mAppSectionsPagerAdapter);
    mViewPager
            .setOnPageChangeListener(new ViewPager.SimpleOnPageChangeListener() {
                @Override
                public void onPageSelected(int position) {                      
                    actionBar.setSelectedNavigationItem(position);
                }
            });

    for (int i = 0; i < mAppSectionsPagerAdapter.getCount(); i++) {         
        actionBar.addTab(actionBar.newTab()
                .setText(mAppSectionsPagerAdapter.getPageTitle(i))
                .setTabListener(this));
    }       
}

public static class AppSectionsPagerAdapter extends FragmentPagerAdapter {

    public AppSectionsPagerAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int i) {
        switch (i) {
        case 0:
            return new WeatherInfoFragment();
        case 1:
            return new PostsFragment();
        default: //TODO method to find which fragment to display ?
            return new LoginFragment();
        }
    }

    @Override
    public int getCount() {
        return 3;
    }

    @Override
    public CharSequence getPageTitle(int position) {
        if (position == 0) {
            return "Weather";
        } else if (position == 1){
            return "Comments";
        }
        else{
            return "Dashboard";
        }
    }
}

@Override
public void onTabReselected(ActionBar.Tab tab,
        android.app.FragmentTransaction ft) {
}

@Override
public void onTabSelected(Tab tab, android.app.FragmentTransaction ft) {
    mViewPager.setCurrentItem(tab.getPosition());
}

@Override
public void onTabUnselected(Tab tab, android.app.FragmentTransaction ft) {
 }
 }

LoginFragment

public class LoginFragment extends Fragment implements AsyncResponse {
Button loginButton;
TextView loginError, login_url;
JSONfunctions task;
JSONObject jsonObject;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    return inflater.inflate(R.layout.login, container, false);
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
}

@Override
public void onStart() {
    super.onStart();

    loginButton = (Button) getView().findViewById(R.id.button_login);
    loginError = (TextView) getView().findViewById(R.id.login_error);

    loginButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {               
            attemptLogin(finalLoginUrl);
            // attemptPost(postURL);
        }
    });
}

private void attemptLogin(String url) {     
        try {
            task = new JSONfunctions(getActivity());
            task.listener = this;
            task.execute(new String[] { url });
        } catch (Exception ex) {
            Log.e("attempt login", ex.getMessage());
        }
    }
}

@Override
public void processFinish(String result) {
    try {
        jsonObject = new JSONObject(result);
        int success = Integer.parseInt(jsonObject.getString("Success"));
        if (success == 0) {             
            // Replace LoginFragment and launch DashboardFragment ?                 
        } else {
            loginError.setText(jsonObject.getString("ErrorMessage"));
        }

    } catch (JSONException e) {
        Log.e("JSON parsing from login result", e.getMessage());
    }
}
}

Answer 1

Was my own fault for not reading the answer here thoroughly. Implemented the code from that answer and got the functionality working :)

Answer 2

I'm not sure this is the best way to handle this but you could define a static boolean inside your MainActivity like so:

public static boolean loggedIn = false;

(e.g. below ViewPager mViewPager;)

And then, in your method processFinish(...) inside the LoginFragment when success is 0 just set MainActivity.loggedIn = true;

This way you can simply put in an if-statement inside your default-case in getItem-method to check whether the user is logged in (if so call the Dashboard-Fragment) or not (display Login-Fragment).

Hope this works for you!

Edit: LoginFragment

public class LoginFragment extends Fragment implements AsyncResponse {
Button loginButton;
TextView loginError, login_url;
JSONfunctions task;
JSONObject jsonObject;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
    Bundle savedInstanceState) {
    return inflater.inflate(R.layout.login, container, false);
}

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
}

@Override
public void onStart() {
    super.onStart();

    loginButton = (Button) getView().findViewById(R.id.button_login);
    loginError = (TextView) getView().findViewById(R.id.login_error);

    loginButton.setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(View v) {               
            attemptLogin(finalLoginUrl);
            // attemptPost(postURL);
        }
    });
}

private void attemptLogin(String url) {     
    try {
        task = new JSONfunctions(getActivity());
        task.listener = this;
        task.execute(new String[] { url });
    } catch (Exception ex) {
        Log.e("attempt login", ex.getMessage());
    }
}

@Override
public void processFinish(String result) {
    try {
        jsonObject = new JSONObject(result);
        int success = Integer.parseInt(jsonObject.getString("Success"));
        if (success == 0) {             
            MainActivity.loggedIn = true;                 
        } else {
            loginError.setText(jsonObject.getString("ErrorMessage"));
        }

    } catch (JSONException e) {
        Log.e("JSON parsing from login result", e.getMessage());
    }
}
}